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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 | /* vi: set sw=4 ts=4: */ /* agetty.c - another getty program for Linux. By W. Z. Venema 1989 * Ported to Linux by Peter Orbaek <poe@daimi.aau.dk> * This program is freely distributable. The entire man-page used to * be here. Now read the real man-page agetty.8 instead. * * option added by Eric Rasmussen <ear@usfirst.org> - 12/28/95 * * 1999-02-22 Arkadiusz Mickiewicz <misiek@misiek.eu.org> * - added Native Language Support * * 1999-05-05 Thorsten Kranzkowski <dl8bcu@gmx.net> * - enable hardware flow control before displaying /etc/issue * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ #include "libbb.h" #include <syslog.h> #if ENABLE_FEATURE_UTMP #include <utmp.h> /* updwtmp() */ #endif /* * Some heuristics to find out what environment we are in: if it is not * System V, assume it is SunOS 4. */ #ifdef LOGIN_PROCESS /* defined in System V utmp.h */ #include <sys/utsname.h> #else /* if !sysV style, wtmp/utmp code is off */ #undef ENABLE_FEATURE_UTMP #undef ENABLE_FEATURE_WTMP #define ENABLE_FEATURE_UTMP 0 #define ENABLE_FEATURE_WTMP 0 #endif /* LOGIN_PROCESS */ /* * Things you may want to modify. * * You may disagree with the default line-editing etc. characters defined * below. Note, however, that DEL cannot be used for interrupt generation * and for line editing at the same time. */ /* I doubt there are systems which still need this */ #undef HANDLE_ALLCAPS #undef ANCIENT_BS_KILL_CHARS #define _PATH_LOGIN "/bin/login" /* If ISSUE is not defined, getty will never display the contents of the * /etc/issue file. You will not want to spit out large "issue" files at the * wrong baud rate. */ #define ISSUE "/etc/issue" /* displayed before the login prompt */ /* Some shorthands for control characters. */ #define CTL(x) ((x) ^ 0100) /* Assumes ASCII dialect */ #define CR CTL('M') /* carriage return */ #define NL CTL('J') /* line feed */ #define BS CTL('H') /* back space */ #define DEL CTL('?') /* delete */ /* Defaults for line-editing etc. characters; you may want to change this. */ #define DEF_ERASE DEL /* default erase character */ #define DEF_INTR CTL('C') /* default interrupt character */ #define DEF_QUIT CTL('\\') /* default quit char */ #define DEF_KILL CTL('U') /* default kill char */ #define DEF_EOF CTL('D') /* default EOF char */ #define DEF_EOL '\n' #define DEF_SWITCH 0 /* default switch char */ /* * When multiple baud rates are specified on the command line, the first one * we will try is the first one specified. */ #define MAX_SPEED 10 /* max. nr. of baud rates */ /* Storage for command-line options. */ struct options { int flags; /* toggle switches, see below */ unsigned timeout; /* time-out period */ const char *login; /* login program */ const char *tty; /* name of tty */ const char *initstring; /* modem init string */ const char *issue; /* alternative issue file */ int numspeed; /* number of baud rates to try */ int speeds[MAX_SPEED]; /* baud rates to be tried */ }; /* Storage for things detected while the login name was read. */ struct chardata { unsigned char erase; /* erase character */ unsigned char kill; /* kill character */ unsigned char eol; /* end-of-line character */ unsigned char parity; /* what parity did we see */ /* (parity & 1): saw odd parity char with 7th bit set */ /* (parity & 2): saw even parity char with 7th bit set */ /* parity == 0: probably 7-bit, space parity? */ /* parity == 1: probably 7-bit, odd parity? */ /* parity == 2: probably 7-bit, even parity? */ /* parity == 3: definitely 8 bit, no parity! */ /* Hmm... with any value of "parity" 8 bit, no parity is possible */ #ifdef HANDLE_ALLCAPS unsigned char capslock; /* upper case without lower case */ #endif }; /* Initial values for the above. */ static const struct chardata init_chardata = { DEF_ERASE, /* default erase character */ DEF_KILL, /* default kill character */ 13, /* default eol char */ 0, /* space parity */ #ifdef HANDLE_ALLCAPS 0, /* no capslock */ #endif }; static const char opt_string[] ALIGN1 = "I:LH:f:hil:mt:wn"; #define F_INITSTRING (1 << 0) /* -I initstring is set */ #define F_LOCAL (1 << 1) /* -L force local */ #define F_FAKEHOST (1 << 2) /* -H fake hostname */ #define F_CUSTISSUE (1 << 3) /* -f give alternative issue file */ #define F_RTSCTS (1 << 4) /* -h enable RTS/CTS flow control */ #define F_ISSUE (1 << 5) /* -i display /etc/issue */ #define F_LOGIN (1 << 6) /* -l non-default login program */ #define F_PARSE (1 << 7) /* -m process modem status messages */ #define F_TIMEOUT (1 << 8) /* -t time out */ #define F_WAITCRLF (1 << 9) /* -w wait for CR or LF */ #define F_NOPROMPT (1 << 10) /* -n don't ask for login name */ #define line_buf bb_common_bufsiz1 /* The following is used for understandable diagnostics. */ #ifdef DEBUGGING static FILE *dbf; #define DEBUGTERM "/dev/ttyp0" #define debug(...) do { fprintf(dbf, __VA_ARGS__); fflush(dbf); } while (0) #else #define debug(...) ((void)0) #endif /* bcode - convert speed string to speed code; return <= 0 on failure */ static int bcode(const char *s) { int value = bb_strtou(s, NULL, 10); /* yes, int is intended! */ if (value < 0) /* bad terminating char, overflow, etc */ return value; return tty_value_to_baud(value); } /* parse_speeds - parse alternate baud rates */ static void parse_speeds(struct options *op, char *arg) { char *cp; /* NB: at least one iteration is always done */ debug("entered parse_speeds\n"); while ((cp = strsep(&arg, ",")) != NULL) { op->speeds[op->numspeed] = bcode(cp); if (op->speeds[op->numspeed] < 0) bb_error_msg_and_die("bad speed: %s", cp); /* note: arg "0" turns into speed B0 */ op->numspeed++; if (op->numspeed > MAX_SPEED) bb_error_msg_and_die("too many alternate speeds"); } debug("exiting parse_speeds\n"); } /* parse_args - parse command-line arguments */ static void parse_args(char **argv, struct options *op, char **fakehost_p) { char *ts; opt_complementary = "-2:t+"; /* at least 2 args; -t N */ op->flags = getopt32(argv, opt_string, &(op->initstring), fakehost_p, &(op->issue), &(op->login), &op->timeout); argv += optind; if (op->flags & F_INITSTRING) { const char *p = op->initstring; char *q; op->initstring = q = xstrdup(p); /* copy optarg into op->initstring decoding \ddd octal codes into chars */ while (*p) { if (*p == '\\') { p++; *q++ = bb_process_escape_sequence(&p); } else { *q++ = *p++; } } *q = '\0'; } op->flags ^= F_ISSUE; /* invert flag "show /etc/issue" */ debug("after getopt\n"); /* we loosen up a bit and accept both "baudrate tty" and "tty baudrate" */ op->tty = argv[0]; /* tty name */ ts = argv[1]; /* baud rate(s) */ if (isdigit(argv[0][0])) { /* a number first, assume it's a speed (BSD style) */ op->tty = ts; /* tty name is in argv[1] */ ts = argv[0]; /* baud rate(s) */ } parse_speeds(op, ts); // TODO: if applet_name is set to "getty: TTY", bb_error_msg's get simpler! // grep for "%s:" if (argv[2]) xsetenv("TERM", argv[2]); debug("exiting parse_args\n"); } /* open_tty - set up tty as standard { input, output, error } */ static void open_tty(const char *tty) { /* Set up new standard input, unless we are given an already opened port. */ if (NOT_LONE_DASH(tty)) { // struct stat st; // int cur_dir_fd; // int fd; /* Sanity checks... */ // cur_dir_fd = xopen(".", O_DIRECTORY | O_NONBLOCK); // xchdir("/dev"); // xstat(tty, &st); // if ((st.st_mode & S_IFMT) != S_IFCHR) // bb_error_msg_and_die("%s: not a character device", tty); if (tty[0] != '/') tty = xasprintf("/dev/%s", tty); /* will leak it */ /* Open the tty as standard input. */ debug("open(2)\n"); close(0); /*fd =*/ xopen(tty, O_RDWR | O_NONBLOCK); /* uses fd 0 */ // /* Restore current directory */ // fchdir(cur_dir_fd); /* Open the tty as standard input, continued */ // xmove_fd(fd, 0); // /* fd is >= cur_dir_fd, and cur_dir_fd gets closed too here: */ // while (fd > 2) // close(fd--); /* Set proper protections and ownership. */ fchown(0, 0, 0); /* 0:0 */ fchmod(0, 0620); /* crw--w---- */ } else { /* * Standard input should already be connected to an open port. Make * sure it is open for read/write. */ if ((fcntl(0, F_GETFL) & O_RDWR) != O_RDWR) bb_error_msg_and_die("stdin is not open for read/write"); } } /* termios_init - initialize termios settings */ static void termios_init(struct termios *tp, int speed, struct options *op) { speed_t ispeed, ospeed; /* * Initial termios settings: 8-bit characters, raw-mode, blocking i/o. * Special characters are set after we have read the login name; all * reads will be done in raw mode anyway. Errors will be dealt with * later on. */ #ifdef __linux__ /* flush input and output queues, important for modems! */ ioctl(0, TCFLSH, TCIOFLUSH); /* tcflush(0, TCIOFLUSH)? - same */ #endif ispeed = ospeed = speed; if (speed == B0) { /* Speed was specified as "0" on command line. * Just leave it unchanged */ ispeed = cfgetispeed(tp); ospeed = cfgetospeed(tp); } tp->c_cflag = CS8 | HUPCL | CREAD; if (op->flags & F_LOCAL) tp->c_cflag |= CLOCAL; cfsetispeed(tp, ispeed); cfsetospeed(tp, ospeed); tp->c_iflag = tp->c_lflag = tp->c_line = 0; tp->c_oflag = OPOST | ONLCR; tp->c_cc[VMIN] = 1; tp->c_cc[VTIME] = 0; /* Optionally enable hardware flow control */ #ifdef CRTSCTS if (op->flags & F_RTSCTS) tp->c_cflag |= CRTSCTS; #endif tcsetattr_stdin_TCSANOW(tp); debug("term_io 2\n"); } /* auto_baud - extract baud rate from modem status message */ static void auto_baud(char *buf, unsigned size_buf, struct termios *tp) { int speed; int vmin; unsigned iflag; char *bp; int nread; /* * This works only if the modem produces its status code AFTER raising * the DCD line, and if the computer is fast enough to set the proper * baud rate before the message has gone by. We expect a message of the * following format: * * <junk><number><junk> * * The number is interpreted as the baud rate of the incoming call. If the * modem does not tell us the baud rate within one second, we will keep * using the current baud rate. It is advisable to enable BREAK * processing (comma-separated list of baud rates) if the processing of * modem status messages is enabled. */ /* * Use 7-bit characters, don't block if input queue is empty. Errors will * be dealt with later on. */ iflag = tp->c_iflag; tp->c_iflag |= ISTRIP; /* enable 8th-bit stripping */ vmin = tp->c_cc[VMIN]; tp->c_cc[VMIN] = 0; /* don't block if queue empty */ tcsetattr_stdin_TCSANOW(tp); /* * Wait for a while, then read everything the modem has said so far and * try to extract the speed of the dial-in call. */ sleep(1); nread = safe_read(STDIN_FILENO, buf, size_buf - 1); if (nread > 0) { buf[nread] = '\0'; for (bp = buf; bp < buf + nread; bp++) { if (isdigit(*bp)) { speed = bcode(bp); if (speed > 0) { tp->c_cflag &= ~CBAUD; tp->c_cflag |= speed; } break; } } } /* Restore terminal settings. Errors will be dealt with later on. */ tp->c_iflag = iflag; tp->c_cc[VMIN] = vmin; tcsetattr_stdin_TCSANOW(tp); } /* do_prompt - show login prompt, optionally preceded by /etc/issue contents */ static void do_prompt(struct options *op) { #ifdef ISSUE print_login_issue(op->issue, op->tty); #endif print_login_prompt(); } #ifdef HANDLE_ALLCAPS /* all_is_upcase - string contains upper case without lower case */ /* returns 1 if true, 0 if false */ static int all_is_upcase(const char *s) { while (*s) if (islower(*s++)) return 0; return 1; } #endif /* get_logname - get user name, establish parity, speed, erase, kill, eol; * return NULL on BREAK, logname on success */ static char *get_logname(char *logname, unsigned size_logname, struct options *op, struct chardata *cp) { char *bp; char c; /* input character, full eight bits */ char ascval; /* low 7 bits of input character */ int bits; /* # of "1" bits per character */ int mask; /* mask with 1 bit up */ static const char erase[][3] = {/* backspace-space-backspace */ "\010\040\010", /* space parity */ "\010\040\010", /* odd parity */ "\210\240\210", /* even parity */ "\010\040\010", /* 8 bit no parity */ }; /* NB: *cp is pre-initialized with init_chardata */ /* Flush pending input (esp. after parsing or switching the baud rate). */ sleep(1); ioctl(0, TCFLSH, TCIFLUSH); /* tcflush(0, TCIOFLUSH)? - same */ /* Prompt for and read a login name. */ logname[0] = '\0'; while (!logname[0]) { /* Write issue file and prompt, with "parity" bit == 0. */ do_prompt(op); /* Read name, watch for break, parity, erase, kill, end-of-line. */ bp = logname; cp->eol = '\0'; while (cp->eol == '\0') { /* Do not report trivial EINTR/EIO errors. */ if (read(STDIN_FILENO, &c, 1) < 1) { if (errno == EINTR || errno == EIO) exit(EXIT_SUCCESS); bb_perror_msg_and_die("%s: read", op->tty); } /* BREAK. If we have speeds to try, * return NULL (will switch speeds and return here) */ if (c == '\0' && op->numspeed > 1) return NULL; /* Do parity bit handling. */ if (!(op->flags & F_LOCAL) && (c & 0x80)) { /* "parity" bit on? */ bits = 1; mask = 1; while (mask & 0x7f) { if (mask & c) bits++; /* count "1" bits */ mask <<= 1; } /* ... |= 2 - even, 1 - odd */ cp->parity |= 2 - (bits & 1); } /* Do erase, kill and end-of-line processing. */ ascval = c & 0x7f; switch (ascval) { case CR: case NL: *bp = '\0'; /* terminate logname */ cp->eol = ascval; /* set end-of-line char */ break; case BS: case DEL: #ifdef ANCIENT_BS_KILL_CHARS case '#': #endif cp->erase = ascval; /* set erase character */ if (bp > logname) { full_write(STDOUT_FILENO, erase[cp->parity], 3); bp--; } break; case CTL('U'): #ifdef ANCIENT_BS_KILL_CHARS case '@': #endif cp->kill = ascval; /* set kill character */ while (bp > logname) { full_write(STDOUT_FILENO, erase[cp->parity], 3); bp--; } break; case CTL('D'): exit(EXIT_SUCCESS); default: if (!isprint(ascval)) { /* ignore garbage characters */ } else if ((int)(bp - logname) >= size_logname - 1) { bb_error_msg_and_die("%s: input overrun", op->tty); } else { full_write(STDOUT_FILENO, &c, 1); /* echo the character */ *bp++ = ascval; /* and store it */ } break; } } } /* Handle names with upper case and no lower case. */ #ifdef HANDLE_ALLCAPS cp->capslock = all_is_upcase(logname); if (cp->capslock) { for (bp = logname; *bp; bp++) if (isupper(*bp)) *bp = tolower(*bp); /* map name to lower case */ } #endif return logname; } /* termios_final - set the final tty mode bits */ static void termios_final(struct options *op, struct termios *tp, struct chardata *cp) { /* General terminal-independent stuff. */ tp->c_iflag |= IXON | IXOFF; /* 2-way flow control */ tp->c_lflag |= ICANON | ISIG | ECHO | ECHOE | ECHOK | ECHOKE; /* no longer| ECHOCTL | ECHOPRT */ tp->c_oflag |= OPOST; /* tp->c_cflag = 0; */ tp->c_cc[VINTR] = DEF_INTR; /* default interrupt */ tp->c_cc[VQUIT] = DEF_QUIT; /* default quit */ tp->c_cc[VEOF] = DEF_EOF; /* default EOF character */ tp->c_cc[VEOL] = DEF_EOL; tp->c_cc[VSWTC] = DEF_SWITCH; /* default switch character */ /* Account for special characters seen in input. */ if (cp->eol == CR) { tp->c_iflag |= ICRNL; /* map CR in input to NL */ tp->c_oflag |= ONLCR; /* map NL in output to CR-NL */ } tp->c_cc[VERASE] = cp->erase; /* set erase character */ tp->c_cc[VKILL] = cp->kill; /* set kill character */ /* Account for the presence or absence of parity bits in input. */ switch (cp->parity) { case 0: /* space (always 0) parity */ // I bet most people go here - they use only 7-bit chars in usernames.... break; case 1: /* odd parity */ tp->c_cflag |= PARODD; /* FALLTHROUGH */ case 2: /* even parity */ tp->c_cflag |= PARENB; tp->c_iflag |= INPCK | ISTRIP; /* FALLTHROUGH */ case (1 | 2): /* no parity bit */ tp->c_cflag &= ~CSIZE; tp->c_cflag |= CS7; // FIXME: wtf? case 3: we saw both even and odd 8-bit bytes - // it's probably some umlauts etc, but definitely NOT 7-bit!!! // Entire parity detection madness here just begs for deletion... break; } /* Account for upper case without lower case. */ #ifdef HANDLE_ALLCAPS if (cp->capslock) { tp->c_iflag |= IUCLC; tp->c_lflag |= XCASE; tp->c_oflag |= OLCUC; } #endif /* Optionally enable hardware flow control */ #ifdef CRTSCTS if (op->flags & F_RTSCTS) tp->c_cflag |= CRTSCTS; #endif /* Finally, make the new settings effective */ /* It's tcsetattr_stdin_TCSANOW() + error check */ ioctl_or_perror_and_die(0, TCSETS, tp, "%s: TCSETS", op->tty); } #if ENABLE_FEATURE_UTMP static void touch(const char *filename) { if (access(filename, R_OK | W_OK) == -1) close(open(filename, O_WRONLY | O_CREAT, 0664)); } /* update_utmp - update our utmp entry */ static void update_utmp(const char *line, char *fakehost) { struct utmp ut; struct utmp *utp; int mypid = getpid(); /* In case we won't find an entry below... */ memset(&ut, 0, sizeof(ut)); safe_strncpy(ut.ut_id, line + 3, sizeof(ut.ut_id)); /* * The utmp file holds miscellaneous information about things started by * /sbin/init and other system-related events. Our purpose is to update * the utmp entry for the current process, in particular the process type * and the tty line we are listening to. Return successfully only if the * utmp file can be opened for update, and if we are able to find our * entry in the utmp file. */ touch(_PATH_UTMP); utmpname(_PATH_UTMP); setutent(); while ((utp = getutent()) != NULL) { if (utp->ut_type == INIT_PROCESS && utp->ut_pid == mypid) { memcpy(&ut, utp, sizeof(ut)); break; } } strcpy(ut.ut_user, "LOGIN"); safe_strncpy(ut.ut_line, line, sizeof(ut.ut_line)); if (fakehost) safe_strncpy(ut.ut_host, fakehost, sizeof(ut.ut_host)); ut.ut_tv.tv_sec = time(NULL); ut.ut_type = LOGIN_PROCESS; ut.ut_pid = mypid; pututline(&ut); endutent(); #if ENABLE_FEATURE_WTMP touch(bb_path_wtmp_file); updwtmp(bb_path_wtmp_file, &ut); #endif } #endif /* CONFIG_FEATURE_UTMP */ int getty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int getty_main(int argc UNUSED_PARAM, char **argv) { int n; char *fakehost = NULL; /* Fake hostname for ut_host */ char *logname; /* login name, given to /bin/login */ /* Merging these into "struct local" may _seem_ to reduce * parameter passing, but today's gcc will inline * statics which are called once anyway, so don't do that */ struct chardata chardata; /* set by get_logname() */ struct termios termios; /* terminal mode bits */ struct options options; chardata = init_chardata; memset(&options, 0, sizeof(options)); options.login = _PATH_LOGIN; /* default login program */ options.tty = "tty1"; /* default tty line */ options.initstring = ""; /* modem init string */ #ifdef ISSUE options.issue = ISSUE; /* default issue file */ #endif /* Parse command-line arguments. */ parse_args(argv, &options, &fakehost); logmode = LOGMODE_NONE; /* Create new session, lose controlling tty, if any */ /* docs/ctty.htm says: * "This is allowed only when the current process * is not a process group leader" - is this a problem? */ setsid(); /* close stdio, and stray descriptors, just in case */ n = xopen(bb_dev_null, O_RDWR); /* dup2(n, 0); - no, we need to handle "getty - 9600" too */ xdup2(n, 1); xdup2(n, 2); while (n > 2) close(n--); /* Logging. We want special flavor of error_msg_and_die */ die_sleep = 10; msg_eol = "\r\n"; /* most likely will internally use fd #3 in CLOEXEC mode: */ openlog(applet_name, LOG_PID, LOG_AUTH); logmode = LOGMODE_BOTH; #ifdef DEBUGGING dbf = xfopen_for_write(DEBUGTERM); for (n = 1; argv[n]; n++) { debug(argv[n]); debug("\n"); } #endif /* Open the tty as standard input, if it is not "-" */ /* If it's not "-" and not taken yet, it will become our ctty */ debug("calling open_tty\n"); open_tty(options.tty); ndelay_off(0); debug("duping\n"); xdup2(0, 1); xdup2(0, 2); /* * The following ioctl will fail if stdin is not a tty, but also when * there is noise on the modem control lines. In the latter case, the * common course of action is (1) fix your cables (2) give the modem more * time to properly reset after hanging up. SunOS users can achieve (2) * by patching the SunOS kernel variable "zsadtrlow" to a larger value; * 5 seconds seems to be a good value. */ /* tcgetattr() + error check */ ioctl_or_perror_and_die(0, TCGETS, &termios, "%s: TCGETS", options.tty); #ifdef __linux__ // FIXME: do we need this? Otherwise "-" case seems to be broken... // /* Forcibly make fd 0 our controlling tty, even if another session // * has it as a ctty. (Another session loses ctty). */ // ioctl(0, TIOCSCTTY, (void*)1); /* Make ourself a foreground process group within our session */ tcsetpgrp(0, getpid()); #endif #if ENABLE_FEATURE_UTMP /* Update the utmp file. This tty is ours now! */ update_utmp(options.tty, fakehost); #endif /* Initialize the termios settings (raw mode, eight-bit, blocking i/o). */ debug("calling termios_init\n"); termios_init(&termios, options.speeds[0], &options); /* Write the modem init string and DON'T flush the buffers */ if (options.flags & F_INITSTRING) { debug("writing init string\n"); /* todo: use xwrite_str? */ full_write(STDOUT_FILENO, options.initstring, strlen(options.initstring)); } /* Optionally detect the baud rate from the modem status message */ debug("before autobaud\n"); if (options.flags & F_PARSE) auto_baud(line_buf, sizeof(line_buf), &termios); /* Set the optional timer */ alarm(options.timeout); /* if 0, alarm is not set */ /* Optionally wait for CR or LF before writing /etc/issue */ if (options.flags & F_WAITCRLF) { char ch; debug("waiting for cr-lf\n"); while (safe_read(STDIN_FILENO, &ch, 1) == 1) { debug("read %x\n", (unsigned char)ch); ch &= 0x7f; /* strip "parity bit" */ if (ch == '\n' || ch == '\r') break; } } logname = NULL; if (!(options.flags & F_NOPROMPT)) { /* NB:termios_init already set line speed * to options.speeds[0] */ int baud_index = 0; while (1) { /* Read the login name. */ debug("reading login name\n"); logname = get_logname(line_buf, sizeof(line_buf), &options, &chardata); if (logname) break; /* we are here only if options.numspeed > 1 */ baud_index = (baud_index + 1) % options.numspeed; cfsetispeed(&termios, options.speeds[baud_index]); cfsetospeed(&termios, options.speeds[baud_index]); tcsetattr_stdin_TCSANOW(&termios); } } /* Disable timer. */ alarm(0); /* Finalize the termios settings. */ termios_final(&options, &termios, &chardata); /* Now the newline character should be properly written. */ full_write(STDOUT_FILENO, "\n", 1); /* Let the login program take care of password validation. */ /* We use PATH because we trust that root doesn't set "bad" PATH, * and getty is not suid-root applet. */ /* With -n, logname == NULL, and login will ask for username instead */ BB_EXECLP(options.login, options.login, "--", logname, NULL); bb_error_msg_and_die("%s: can't exec %s", options.tty, options.login); } |